Fiber optic connectors of a wide variety of designs have been employed to terminate optical fiber cables and to facilitate connection of the cables to other cables or other optical fiber transmission devices. A typical optical fiber connector includes a ferrule which mounts and centers the optical fiber within the connector. The ferrule is mounted in some form of ferrule holder which is assembled within another body member of the connector. The ferrule may be fabricated of such material as ceramic, and the ferrule holder typically is molded from plastic material. When the ferrule holder is assembled within the body member of the connector, it is biased by a spring such that the ferrule yieldably projects from the connector for engaging another fiber-mounting ferrule of a mating connecting device. A pair of connectors often are mated in an adapter which centers the fibers to provide low insertion losses. The adapter couples the connectors together so that their encapsulated fibers connect end-to-end.
Various problems are encountered when terminating optical fibers in fiber optic connectors versus terminating electrical conductors in electrical connectors, when situations arise wherein a fiber end of an "active" fiber optic connector is exposed. A typical situation might arise when one of the fiber optic connectors at one end of an adapter is removed, leaving the other "active" fiber optic connector in the adapter.
In particular, an exposed fiber end may be damaged by adverse environmental hazards, and the accumulation of dust and dirt may impair the optical transmission capabilities of the fiber. Another very important problem is to protect an operator's eyes from dangerous light beams from the exposed end of an active optical fiber. For instance, an operator's eyes may be damaged from dangerous light beams exiting an unprotected receptacle or adapter.
Heretofore, dust covers, end caps or spring-loaded shutters have been used to close an open end of an adapter to, thereby, cover the exposed fiber ends to protect the fiber ends from adverse environmental hazards and to prevent light energy from the fiber ends from exiting the adapter. Many of these apparatus are quite complicated and require that the adapter either be modified or custom designed with the dust cover, end cap or spring-loaded shutter.
On the other hand, there are many adapters presently in use which do not have such protective apparatus. It would be desirable to be able to use existing or conventional adapters with a protective shutter or shield without extensively modifying the adapter. For instance, one popular conventional or standard optical fiber connector for which adapters are provided is known as an SC connector. An SC connector is connected to another SC connector through an adapter by linear motion only. Another popular conventional or standard optical fiber connector for which adapters are provided is known as an FC connector. Two FC connectors may be placed in optical connection with each other through an adapter. Each FC connector is assembled to the adapter by turning threadably each FC connector onto an externally threaded portion of the adapter.
The present invention is directed to solving the various problems identified above by a protective shield or shutter which can be used with an adapter for a conventional or standard fiber optic connector, without modifying the adapter in any way. As disclosed herein, the invention is embodied in an adapter for coupling one or more FC connectors.